Devices for packing stacks (groups) of filled tea bags in which a stack of tea bags is fixed within a channel by a stack holder and a stack pusher are known. The devices have a rotor arranged downstream of the channel with at least two cassettes for receiving the fixed stack of tea bags and further have a transport device comprising a further stack holder and a further stack pusher for transporting the stack of tea bags from the rotated cassette into a position above a packing box. A pushing device for pushing the stack of tea bags into the box is also provided.
In a device disclosed in German Offenlegungsschrift 24 12 063 the filled tea bags are transported in an upright position by a feeding device, are separated into groups by separating elements, and are then engaged serially by stack holders and stack pushers. After transfer to the cassette the stack of tea bags is rotated, shook, and compressed before being pushed into the waiting packing box. In this manner it is to be achieved that the contents of the tea bag is substantially uniformly distributed and compacted to such a degree that the stack of tea bags fits into a box of a predetermined length.
In general, such a device is designed for packing stacks of tea bags of the same size with a predetermined number of tea bags. In order to adjust, if needed, the number of tea bags of a stack to the corresponding available volume of the box to be used, long change-over times are required which result in long and undesirable downtimes for the machine. Furthermore, it should be noted that the conditions for maintaining an optimal distribution of the tea bag contents constantly change as the number of tea bags of a stack changes and also as a function of the consistency (quality) of the tea so that for a high machine output only a limited amount of time is available to adjust the known devices to the changing conditions. Disturbances of the production therefore can be hardly avoided, even with such complicated measures as the additional shaking of the tea bags in the cassettes.
From German Offenlegungschrift 18 00 245 a further device for forming stacks of tea bags and for insertion of the stacks into packing boxes is known. This device places the tea bags within one stack alternatingly upright and upside down. Thus, the stack forms within the box a compact shape on edge which however requires some adjustment by the customer since every other tea bag is upside down when removed from the box. With this known device changes of the number of tea bags within one stack can only be achieved with great difficulties.
It is therefore an object of the present invention to provide a device of the aforementioned kind with which changes of the number of tea bags within a stack for an optimal use of the available space within the box is possible without problems whereby a substantially uniform tea distribution in the tea bags should be maintained during the entire packaging process.